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Technical Consultant · Engineering Leader · Technical Architect · Staff Engineer

Vishnu Balachandran

I build resilient systems and lead teams that ship.

Technical Consultant and Java technical expert with 8+ years building resilient banking and fintech platforms.

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Vishnu Balachandran
years building production systems
8+
companies shipped for
5
self-paced courses
12
first call to scope your problem
Free
Previously at ZafinWay.comUdaan.comSunTec Business SolutionsFlyTxt Mobile Solutions

My story

Find what's actually broken. Fix the real cause.

Full background →

Eight years ago I was at FlyTxt, chasing slow code paths in a telecom CRM platform, and one profiling pass cut latency 10x. Today I architect the Java and Spring Boot microservices behind the pricing and billing engine a bank’s deal desk runs on every day, 2M+ transactions at sub-second latency, and lead the engineers who build it. The through-line is one instinct: find what is actually broken and fix the real cause.

Read the full story

It is event-driven on Kafka and PostgreSQL, secured with OAuth2, Keycloak, and JWT, and deployed on Azure (AKS, ArgoCD, Terraform) and AWS (EC2, EKS, S3, SQS). At Way.com I moved authentication to OAuth2 and built idempotent Stripe payments. At Udaan a custom API gateway took uptime from 99.5 to 99.95 percent and cut latency 45 percent.

For 4+ years I have led teams of 10 to 30 engineers, including a Spring Boot upgrade across 20+ microservices that cleared 15+ CVEs. An architecture only holds if the team building it does too.

For about four years I have put AI to work inside that stack: an OpenAI-powered Pricing and Billing Copilot (Python, FastAPI, PyTorch) that halved L1 support resolution time and made me an AI Build Day 2026 finalist, and the RAG assistant on this site, built on a vector database with Hugging Face and NVIDIA models. Outside the day job I build end to end: this portfolio, and Temple Accounts and Billing, sold here as a downloadable product. If you are trying to get a system like these right, get in touch.

What I work in

Open any area for what I've actually built with it, and the tools involved.

  • Microservices architecture
  • Event-driven architecture
  • Kafka (Avro schema registry)
  • Apache NiFi
Distributed Systems & Event Streaming Expert

Built Way.com's API gateway for 5M+ daily requests at 99.95% availability, with Resilience4j, Redis, and Spring Cloud Gateway. At Zafin a Kafka-partitioned delta-processing ETL cut data-load time by 60%.

  • Microservices architecture
  • Event-driven architecture
  • Kafka (Avro schema registry)
  • Apache NiFi
  • Elasticsearch
  • DDD / CQRS / Clean Architecture
  • System design
  • Design patterns (GoF)
  • API Gateway
  • PyTorch
  • Hugging Face
  • OpenAI API
  • Anthropic Claude API
GenAI & LLM Engineering Advanced

Built Zafins AI-powered Pricing and Billing Copilot: a PyTorch-based chatbot that self-trains on past queries and the answers that resolved them, cutting L1 support resolution time 50%. Also designed this sites own RAG pipeline, embedding its content with NVIDIA and Hugging Face models so its AI Assistant answers grounded in real site content.

  • PyTorch
  • Hugging Face
  • OpenAI API
  • Anthropic Claude API
  • NVIDIA API
  • RAG pipelines
  • Vector databases (pgvector/Pinecone/Weaviate)
  • LangChain4j
  • LangGraph
  • AutoGen
  • CrewAI
  • FastAPI
  • SSE streaming
  • MLOps (MLflow/SageMaker/Kubeflow)
  • Java 21
  • Kotlin
  • Spring Boot
  • Spring Cloud
Languages & Frameworks Expert

Upgraded Spring Boot across 20+ microservices and eliminated 15+ CVEs. At FlyTxt, JProfiler and Hibernate tuning delivered a 10x latency reduction on the serving path.

  • Java 21
  • Kotlin
  • Spring Boot
  • Spring Cloud
  • Spring Batch
  • Spring Data JPA
  • Hibernate
  • Resilience4j
  • Netflix OSS
  • Pricing engines
  • Billing & invoicing
  • Deal & arrangement management
  • Profitability analysis
Domain: Banking & Fintech Expert

Zafin's Corporate Pricing Engine prices and bills 2M+ transactions a day at sub-second latency. I was technical SPOC for Deal Manager's first production go-live at ING Bank, at 99.9% uptime on day one.

  • Pricing engines
  • Billing & invoicing
  • Deal & arrangement management
  • Profitability analysis
  • AUM calculations
  • Portfolio & custody operations
  • Technical leadership
  • Engineer mentorship
  • Stakeholder & executive communication
  • Agile / Scrum
Leadership & Mentorship Expert

Mentored 10+ engineers at Zafin; SOLID and CQRS adoption cut defect leakage 40%. At Way.com I led 30+ features and pulled feature time-to-market from 6 weeks to 3.

  • Technical leadership
  • Engineer mentorship
  • Stakeholder & executive communication
  • Agile / Scrum
  • Cross-functional team leadership (10-30+ engineers)
  • Azure AKS
  • AWS EC2
  • AWS EKS
  • AWS S3
Cloud & Containers Advanced

Automated AWS/EKS deployments at SunTec, cutting manual effort 80%. At Udaan I ran the API gateway on Azure with Resilience4j, dropping P99 latency 35%.

  • Azure AKS
  • AWS EC2
  • AWS EKS
  • AWS S3
  • Docker
  • Kubernetes
  • Azure DevOps
  • GitHub Actions
  • Jenkins
  • ArgoCD
Delivery & Observability Advanced

Canary releases, A/B tests, and feature flags at Udaan cut deployment incidents 70% and doubled release velocity. Prometheus, Thanos, and Grafana brought MTTD from 15 minutes to under 3.

  • Azure DevOps
  • GitHub Actions
  • Jenkins
  • ArgoCD
  • CI/CD & GitOps
  • Prometheus / Grafana / ELK
  • Playwright
  • k6
  • Allure
  • PostgreSQL
  • Liquibase
  • Azure FlexiDB
  • CrunchyDB
Databases & Caching Advanced

PostgreSQL is the system of record behind Zafin's event-driven pricing engine at 2M+ transactions a day. Redis caches Way.com's 5M+ daily-request gateway; Ignite Cache backs SunTec's streaming billing and payments.

  • PostgreSQL
  • Liquibase
  • Azure FlexiDB
  • CrunchyDB
  • Oracle
  • MySQL
  • MongoDB
  • Azure CosmosDB
  • Redis
  • Ignite Cache
  • Claude Code / Cursor / Codex
  • Model Context Protocol (MCP)
  • Architecture docs as RAG context
  • CLAUDE.md / AGENTS.md rule files
AI-Assisted & Agentic Engineering Advanced

Built Zafin's AI Pricing & Billing Copilot, cutting L1 resolution time by 50%. It sits on the live pricing and billing platform, not a side demo.

  • Claude Code / Cursor / Codex
  • Model Context Protocol (MCP)
  • Architecture docs as RAG context
  • CLAUDE.md / AGENTS.md rule files
  • Context & prompt engineering
  • AI-assisted code review
  • REST API design
  • Hasura GraphQL
  • Temporal.io workflow orchestration
  • Keycloak / JWT auth
Integration, Workflow & Frontend Proficient

Shipped 30+ Way.com features and partner integrations — Amazon, getUpside, FuelRewards, Travelers, Cure — adding $1M+ incremental ARR. Client teams consume those through the REST and GraphQL APIs I designed.

  • REST API design
  • Hasura GraphQL
  • Temporal.io workflow orchestration
  • Keycloak / JWT auth
  • React
  • TypeScript